var hours = document.querySelector('.fivetime .hours');
var minute = document.querySelector('.fivetime .minute');
var seconds = document.querySelector('.fivetime .seconds');
var aftertime = +new Date('2020-10-03 19:00:00');

setInterval(function(){
    var nowtime = +new Date();
    var time = (aftertime - nowtime) / 1000;

    var h = Math.floor(time / 60 /60);
    var m = Math.floor(time / 60 % 60 );
    var s = Math.floor(time % 60);

    h < 10 ? h = '0' + h : h;
    m < 10 ? m = '0' + m : m;
    s < 10 ? s = '0' + s : s;

    hours.innerText = h;
    minute.innerText = m;
    seconds.innerText = s;
}, 1000);